The trial, led by STOP member Alejandro Krolewiecki, shows that the combined use of albendazole and high-dose ivermectin is highly effective against whipworm

Children reading on steps. Credit: GPE/Paul Martinez


Trichuris trichiura (or whipworm) is an intestinal parasite transmitted via eggs that   contaminate the soil, food or water.  Whipworm, together with round worm (Ascaris lumbricoides), and hookworms (Necator americanus and Ancylostoma duodenale) and threadworm (Strongyloides stercoralis), belongs to the group of soil-transmitted helminths (STH). STH are widely spread in tropical and subtropical regions with poor sanitation and is most frequent among children. While these infections are rarely lethal, they do have a great impact on children’s health: they cause stomach pain, diarrhoea, anemia, and can affect cognition and school performance.

Since 2012, the World Health Organisation recommends mass administration of a drug called albendazole to school-children, in order to prevent STH infections and reduce, and eventually eliminate, their transmission. However, the efficacy of albendazole against whipworm is much lower than for other STH. This means that, with the current treatment, it will not be possible to stop its transmission. This is why the STOP project is evaluating the efficacy of combining ivermectin and albendazole to treat STH. Why ivermectin? Because it is a drug that has been shown to kill Trichuris as well as other parasites. The main novelty of the project is combining a fixed dose of both drugs in one single tablet, in order to facilitate its mass administration.

Alejandro Krolewiecki, member of the STOP consortium, has provided valuable evidence supporting this strategy. He and his team led a clinical trial in two rural towns of Honduras to evaluate the efficacy of giving ivermectin in addition to albendazole to children (ages 2 to 14) for the treatment of Trichuris. The trial results show that the combination using the highest dose of ivermectin, given either once or consecutively for three days, was highly effective (with a cure rate of 100% and 88.6%, respectively) and was well tolerated.

“These results show that high-dose ivermectin offers a significantly improved treatment for whipworm infection,” says Krolewiecki, “and are very positive for our STOP project.”



Matamoros G, Sanchez A, Gabrie JA et al. Efficacy and safety of albendazole and high-dose ivermectin co-administration in school-aged children infected with Trichuris trichiura in Honduras: A Randomized Controlled Trial. Clin Infect Dis. 2021 Apr 27;ciab365.